Young men are being warned they risk losing their job, being barred from travelling overseas or being sent to jail if they get caught up in the increasing number of street assaults.

Gardai say young men aged 18 to 39 are most likely to be involved in attacks which typically occur between 8pm and 5am at the weekend.

A quarter of incidents linked to this night-time economy involve drink, gardai said.

The campaign to reduce violent street attacks also revealed that gardai believe about 40% of the incidents are not reported and only 41 of the more than 7,000 assaults recorded last year were classed as racially motivated.

Only 3% involve repeat offenders.

Sergeant Kelvin Courtney, of the Garda bureau of community engagement, urged young men to think about the impact of their actions on themselves and others.

"The vast majority of assaults that occur are needless and avoidable," he said.

But the officer urged people to come forward and report crimes, despite concerns about being embarrassed by being a victim.

"Some victims of assaults, particularly men, are embarrassed to say they have been assaulted," Sgt Courtney said.

"I would encourage anybody, and in particular younger men, to report all assaults to An Garda Siochana.

"Anyone who has been assaulted will be treated with sensitivity by An Garda Siochana and it will be fully investigated."

The Garda public awareness campaign has been titled "Use Your Brain Not Your Fists" and is targeting men aged between 18 and 39.

The force's records show th e number of assaults causing harm in Dublin rose from 1,396 in 2012 to 1,707 in 2015, while minor assaults increased from 3,100 to 3,337 in the same period.

But this year nationwide figures show the number of assaults have declined.

Other figures showed 83% of offenders in assault cases are men, 70% involve men attacking men and three quarters of victims are men.

Gardai warned about the impact on victims who suffer serious physical harm and psychological damage such as loss of confidence or anxiety and the ramifications for offenders who end up with a criminal record.

The increase in assaults was revealed by gardai to the Policing Authority in June.

The force's head of analysis, Gurchand Singh, said it was directly related to busier streets at night as the economy improves and followed a fall in the same category from 2008 to 2011.